Clutch-band for friction-clutches.



PATBNTED DBC. 25, 1906'.

0.J.JAGER.v y CLUTCH BAND FOR PBlCTIoN GLUTGHES.

APPLICATION FILED 11213.13. 1905.

Quinnrll wel Perl Il.. Manuf... l-

CHARLES J. JAGER, OF BOSTON, MASSACHUSETTS.

CLUTCH-BAND FOR F RiQTION-CLUTCHES.

Specification Letters Patent.

Patented Dec. 25, 1908.

Application filed Februar-'y 13, 1905. Serial Ne. 245,424.

.T all whom if Inl/y concer/lf:

Be it known that I, CHARLES J. JAGER, a citizen of the United States, residing at Boston, in the county of Suffolk, State of Massachusetts, have invented a certain new and usr-ful Improvement in Clutch-Bands for Friction Clutches, of which the followlmg 1s a specification, reference being had therein to the accompanying drawings.

My invention relates to certain nov. and useful improvements in clutch-bands for friction clutches used in power transmission, hoisting, or other machinery, in which the friciion clutch-band is carried by one clutch member and i5, by means of suitable mechanism, caused to bear forcibly againsr the surface of-a drum fixed to thel other clutch member, thereby caug'ng rie-- tional contact between clutclbband and drum which renders the clutch members irrevoluble with respcct to each other. i

lt is well Known that helical clutch-bands v are well adapted for use in clutch members.

by reason of the fact that when properly feb portioned and arranged a slight initial ap-A plication of tightening movement to the free end of the helical band causes the same to tighten throughout its entire length upon tLe drum-surface with great gripping force. This self-tightening feature is, however, objectionable, for the reason that the engagement of the clutch members is usuallyr accompanied by a violent jerk er jump, which throws an undue strain upon the. clutch mechanism, and is otherwise objectionable.

My invention has for its object the production of a clutch mechanism in which are embodied the self-tightening and other advantages of the helical clutch-band, with the elimination of tie objectionable features usually accompanying the engagement of the clutch members, the said clutch being of an evenly-balanced construction to insure smoothrt'lming, simple in adjustment and manipulation, and reliable in operation.

1n the accompanying drawings, Figure 1 shows a side view, partially in section, of a clutch embodying my invention, the clutch being shown in th"l position of engagement. Fig. 2 is a section ef the same essentially on the plane :n the hub portion of 1 being omitted. Fig. 3 shows the clutch-band detached from the rest of the clutch. mechanism. a

Referring to the drawings, 1 represents one of the clutch members, the same being shown as freely revoluble upon the main shaft 2. Preferably integral with 1 is a cylindrical drum 3, affording a bearing-surface for the clutch-band comprising the two component elements 40 50, as hereinafter set forth, encircling the sane, The other clutch member 4 consists, as here shown, of a hub 5, fixed as to shaft 2 by means of the key 6 or other appropriate fastening device and provided with arms 7 7, radiating therefrom. The said arms 7 7 carry at their extrem'ties bosses 8 S, having revolubly journal therein, preferably Parallel with shaft 2, the shafts or rockers 9 9, forming a part of the clutch-bandtightening mechanism.

Fixedly mounted upon one end of shafts t. 9 by means of pins 1() 1() are the clutchband-tightening dogs 11 11, bearing against the projections 4S 5S on the free end of clutch-band 40 50. The other ends of shafts 9 9 carry, preferably pinned thereto, the lever-arms 12 12, extending from the said Shefts f) 9 inwardly, but passing t0 oeside of main shaft 2, and of auch tltg that the ends 13 13 of the lever-arms 12 12 bear against the surface of a sliding collar 14. Collar' 14 is longitudinally movable upon main shaft 2 by means of any suitable mecl1- anism (not shown in the drawings) and which may engage the collar by means of the groove 15, provided in one end of the same. Y In Fig. 1 the collar 14 is shown in full lines in its operating osit-ion and in dotted lines in its position w ien the clutch members are not in engagement. The end of collar 14 which is adjacent the clutch member 5 consists of a tapering surface 16, termfnating in a cylindrical portion 17. The dimensions of the tapered and cylindrical portions of collar 14 and the length and amount of inward inclination of the lever-arms 12 12 are such that when the clutch members are unengaged and the sliding collar 14 is moved upon main shaft 2 from its extreme position vat the right of Fig. 1, as shownby dotted lines, leftward in the direction of clutch member 1 the smaller end of the tapering surface 16 first engages the ends 13 13 of the lever-arms 12 12 and with the continued movement of 14 forces them outwardly from main shaft 2. The said ends 13 13 finally rest upon the cylindrical portion 17 of collar 14 in the position of complete 'engagement of the clutch members, as shown in Fig. 1.

The clutch-band 4() 50 is preferably made of bronze or of some tough and elastic mate` rial which combines a great tensile strength with wear-resisting qualities. As shown in the drawings, the said clutch-band consists of two similarly-formed components 4() and 5l), each of which is ahelix having slightly over one and one-half turns about drum 3. The coils of Aeach helix are opened, so as to iermit the coils of the companionhelix to lie adjacent' to'or intermediate to its own coils, so that t' helical bands lie alternately, with their respective edges preferably nearly contiguous upon the surface of drum 3. This arrangement may be seen more clearly by referring to Fig. 3 of the drawings, in which one helical component 40, starting at 41, completes approximately its trst half-turn about the drum 3 at 42, the full turn at 43, and ends at 44, comprising slightl over one and one-half turns in all. ln similar manner the companion helicai band 5t), commencing at 51, substantially diametrically opposite to 41, eon'ipletes approximately the half-turn at :'32, the full turn at 525, and the whole length, comprising slightly over one and onehalf turns, is completed at 54.

The clutch-band comprising the two component helices comoiued as above pointed out is bored internally so that in the normal condition (corresponding with a position when the clutch members are not engaged) it. freely revoluble upon the drum 3. Adjustable bearing-screws and 5.5, provided with lock-nuts 46 and 56, mounted in the lugs 4T and 57, irojecting, respectively, from the clutch-band components 4l) and 5U near the ends 41 andil of the same, bear upon the exterior of the bosses S 8 and prevent rotation of the clutch-band components with respect to clutch member 5. At or near the other or free ends of each of the said clutch-band components 40 and 5() are the pro'ections 48and 5S, adapted to engage with the band-tightening dogs 11 11.

The operation of the clutch mechanism is y as follows: ihen the clutch members are out of engage1uent,-the collar 14 is in its extreme right -hand position, as shown by dotted lines inl `ig. 1. VTo throw' the clutch members into engagement, the collar 14 is moved toward the left in Fig. 1, causing the tapering surface 1G to bear against the ends 13 13 of the lever-arms 12 12. As the leftward movement of collar 14 continues the increasing diameter of the tapering surface .1.6 forces the ends 13 13 of the lever-arms 12 12 outwardly from shaft 2, causing a right-handed rotation of the shafts 9 9, journaled in the bosses 8 8, and a consequent right-handed rotation of the band-tightening dogs 11 11. A continued leftward movement of collar 16 will cause further rotation of dogs 11 l1 and a consequent circumferential movement of the free ends of the clutch-band components, and since the screws 45 and 55, bearing upon the bosses 8 8,prevent further rotation of the clutch-band components upon the drum 3 the circumferential nio\ ement of the free ends of the clutch-band helical components will eii'ect such a diminution in the internal diameter of the coils as to cause them to grip the druln 3. Finally, when collar 16 has reached the limit of its leftward movement, occupying the position shown in Fig. l, the ends 13 13 of the levcr-arms 12 12 rest upon the cylindrical surface 17 ol' collar 14,l in which position the outward movements of arms 12 12 have been sullicient to rotate dogs 11 11 and to cause a circumferential movement of the free ends oi' the c-lutehband components to such a degree that the clutch -band will grip the drum 3 with enough force to transmit the power desired.

On desiring to throw the clutch members` out of engagement the collar 14 is moved toward the right from the position shown in Fig. 1, whereupon the elasticity of the clutchband components causes them to resume their normal condition, releasing the drum 3 from their grip and restoring dogs 11 11 and lever-arms 12 12 to their normal initial positions.

To insure the most satisfactory results, it has been found desirable to adjust the bearing-screws45 and 5.5 so as to cause one clutchband component to grip the drum 3 slightly before its companion component. The e'ect of this will be that the clutch-band component which first engages the drum will tighten in the manner characteristic to helical bands throughout its entire length upon the drum-surface, but not having s lllcient gripping-surface to transmit the fuli power of the clutch will slip on the druln until further movement of the tightening mechanism causes the companion clutch-band to take hold, when the combined gripping effect of both components will transmit the full power of the clutch without slip. llflien, however, a clutch -band comprising a single helix which has a gripping-surface and consequent driving power equivalent to that of the double helical band is used, the initial application of tightening force to the free end oi` the hand will causeA its coils to take hold along their entire length, bringing its total gripping power into ei'ect at once. This sudden application of full gri )ping power will not allow the clutch mem ers to slip while engaging, with the result that they engage with a violent jerk, which is objectionable vfor obvious reasons.

In my clutch, for the reasons above pointed out, any tendency to jum or jerk, due to the sudden engagement of tliie clutch members, is minimized.

While 1 have hereinabove described my invention as applied in a clutch-band having two component members, three or more component members may be used, in which case 't1-,hey should preferably be provided with ini in.)

dividual adjusting and tightening devices provided with adjustable contact-screws 45,

o craftingr in the manner above set forth, and e utch member 5 should be formed with a corresponding number of arms. Moreover, the number of coils in each helical component may be increased if necessitated by the power requirements in any special case.`

lt is also evident that my invention may be applied to friction-clutches Wherein'the clutch-band embodying substantially the features hereinabove set forth is caused to expand against the adjacent internal surface of a drum, in which case the necessary mechanical modifications of the tightening and adjusting mechanisms above described may be readily made by any mechanic conversant wi th the art. Furthermore, for the cylindrical frictiondrum,7 so called, maybe substituted a drum havin T a. conical or tapering surface, the clutch-band in this case being formed with a corresponding taper and being adapted to engage either externally or internally with the tapering surface of the drum. l-laving described my invention, what I claim as my invention, and desire to secure by Letters Patent, is-- 1. In a friction-clutch, in combination, the driven member having.,r the barrel or drum portion, the driving member having a plurality of rockers journaled therein, operating vmeans for said rockers, a plurality of clutchbands encircling the said barrel or drum pertion, respectively furnished at one end with lugs that are acted against by dogs fast on the res )ectlve rockers and at the other end 55, abutting on said driving member.

2. In a friction-clutch, in combination, the driven member having the barrel or drum portion, the driving member having a plurality of rockersjolirnaled therein, operating means for said rockers, and a pluralit ofv clutch-bands encircling the said barre 0r drum portion in alternating or interlying helical coils, each band extending more than once around the said drum or barrel and the said bands being in operative connection with the said rockers.

3. In a friction-clutch, in combination, a clutch member having a drum or barrel, a second clutch member having radial arms provided with the bosses S, 8, the shafts 9, 9, journaled in the said bosses and provided at one end with the dogs 11, 11 and at the other end Wit-h the lever-arms 12, 12, the sliding collar 14 by which the lever-arms are actuated, and a plurality of clutch-bands helically Wound upon the said drum or barrel in interlying coils, the said bands being provided at one end with the adjustingscrews 45, 55, which bear against the bosses 8, 8, and at the other end with the projections 4S, 5S, which are engaged by the dogs 11, 11.

In testimony whereof I alix my signature in presence of two witnesses.

CHARLES J. JAGER.

\Vitnesses NATHAN B. DAY, WILLIAM A. COPELAND. 

